Evaluation of groundwater movement in the Frenchman Flat CAU using geochemical and isotopic analysis

The principal pathway for radionuclide migration from underground tests in Frenchman Flat, on the Nevada Test Site, to the accessible environment is groundwater flow. Two potential pathways for radionuclide transport via groundwater have been identified from hydrologic data: (1) radionuclide transport downward from the alluvial and volcanic aquifers into the underlying carbonate aquifer; and (2) radionuclide transport laterally to the carbonate aquifer surrounding Frenchman Flat. This report presents an evaluation of geochemical and environmental isotopic data to test these potential pathways and to identify other groundwater flowpaths in, and out of, Frenchman Flat.